Surface Plate & Height Gauge recommendations

Point taken Andrew I should have thought about it a bit more.

Ron

Well that's odd; before I started breakfast I'm sure there was a post in this thread by JasonB explaining to Barrie and I that we knoweth not what we talk about with regard to SoD and grinders. But it now seems to have disappeared? May be SoD has more influence than we realise, and we should be careful in case the boys call round for a 'chat'.

Andrew

There was, I did not read the last bit of Dave's post, the rest was about grinding granite which my reply related to so deleted it after re-reading Dave's post.

So out of interest I mounted the test indicator on a Stevenson block for stability and took a number of readings around the plate. Wont bore you with the details but basically the plate has a central area approx 10 x 8 inches which is good to 0.025 mm. You can see in the pic the indicator reading with the indicator towards the left of the plate having set zero 10 inches away on the right of the plate. From this central area the plate falls away towards the corners 0.5 mm at two corners with 0.7 and 1.0 at the other two.

I also did a basic test with a 4 inch gauge block and a strong torch looking for any obvious hollows, high spots ripples etc but didnt find any.

So as a surface plate it is not good but as a general purpose plate which has a decent centre section which will cover what I will be using it for its good, very good if you consider it cost £10 from a kitchen shop.

Edited By Ron Laden on 05/06/2020 09:03:59

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At least I'm not losing my marbles, ground or otherwise.

Andrew

Absolutely agree. SoD is infallible! My mum thinks he's gorgeous too...

Fantasy over. The claim in favour of grinding comes from Industry taken as a whole. As manufacturing developed over the centuries, every effort has been made to replace toothed metal cutting with some other process. Either because the alternative is cheaper or is more accurate or both. Casting, Rolling, Stamping, Extrusions, Gas Axe, Lasers, Water Jet, Spark Erosion, Chemicals, Forging, Grinding and many more techniques are in the game.

Possibly the forum's deep interest in lathes, milling machines, files and saws leads us to lose the big picture? Whilst 'our' methods dominated industry into the early 20th century, not so today. Time marches on. Not only are more production processes available now, but machinable metals are often replaced with plastics, ceramics, and difficult metals that don't mill or turn well. For that reason manual lathes and mills are rarely found on production lines.

Have a wander round and ask how each product in the home was made and how much of it involved a lathe or milling machine. Take cutlery: there are nearly 8 billion people on the planet and most of them use knives, all made by rolling, stamping and grinding. Many other common objects avoid cutting too. Screw fasteners are rolled. Precision threads are ground. Opening up a printer, TV set, vacuum cleaner, fridge, boiler or even a car engine won't find many milled or turned components in it. Most of my workshop tools are ground, including the lathe's ways and the milling table.

Plenty of counter examples because toothed cutting is still the best way of tackling many jobs, but it's not nearly as ubiquitous as it used to be. Any Production Engineers on the forum?

Dave

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There were a couple of Lumsden grinders in our machine shop but even though they are the king of grinders for material removal I don’t think they would trouble the rest of the machines in the shop for removal rate

Mike

I work for a major engine manufacturer and we avoid grinding as much as possible, mostly due to speed. If you want to machine an engine block every 30 seconds, you cut using edged tools. The only components using grinders are cranks & cams and that's a finish grind for the last couple of microns. Which is slow because the wheel has to be dressed after each journal. So very little metal removal and a lot of dirt.

Modern high speed CNC machines are perfectly capable of milling, turning, boring without the need to grind. Tool changing is automatic and without stopping production which cannot be done with grinding wheels.

Not as esoteric as some and cheaper than most. My two surface plates are ex electronics cabinet de humidifiers, "Warmers",  that were caught on the way to the skip. All traces of heating elements removed, and ground where it matters. They are about 300mm x about 220mm. The height gauge is a metric APE Microball that was also redirected on when on its way to the skip. I've just had a look on the local ebay and they seem to be fairly readily available and quite reasonable. The surface plates are excellent for what I use them for, and the height gauge is consistent, accurate and easy to use.

It's very easy to over think this stuff sometimes!!

cheers

Bill

Edited By Bill Pudney on 05/06/2020 12:14:44

Edited By Bill Pudney on 05/06/2020 12:15:30

Well out of curiosity of looking at the new Kitchen counter top, engineered stone. With the light and reflections looks fairly flat. I set up a dti and a plate with 3 point and moved it around the place. The whole area is better than 0.04mm. The majority of the centre area is well better than 0.02mm. So instead of buying a 1m granit plate for the shop,when she is not home, the kitchen top will work just fine. Thanks for the heads up on that. I have no idea how they even get them that good. Not often I am marking out pieces longer than 300 mm. But when needed have ample space as long as it is not heavy, oily or will not scratch the top. Just have to make sure the height gauge base is clean first.

Must be my lucky day, on Ebay I put an offer in on a Mitutoyo APE Microball 12 inch height gauge and its been accepted..

Its said to be in good condition and complete with its wooden case.

Edited By Ron Laden on 05/06/2020 12:31:38

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The APE height gauge arrived, used but in nice condition quality is excellent. Accurate too, when checked against my gauge blocks its spot on. I really like the micrometer adjustment, super smooth and feels just right. I put an offer in on ebay and got it for £30, can't complain at that.

Very nice too, Ron !!

MichaelG.

Good things come to those who work in imperial!

Actually I work mainly in metric Lee but I,m happy in both. When it comes to tolerances and tighter dimensions for some reason I see and can relate to thou easier than I can parts of a mm. So hence the imperial height gauge, my mic is imperial also.

Ron

I have a Shardlow conventional height gauge. I first used one as an apprentice and liked the fine feed adjustment which is engaged with a lever. I preferred it to the Chestermans which we also used. A digital height gauge has the useful feature that zero can be anywhere you like but with a conventional one the surface plate is always zero. You will need to be handy with mental arithmetic to mark out anything that is not datumed from the surface plate and dimensioned from that datum.
Mike